It is often necessary to fit flow devices to existing plumbing installations. In many instances, it can be difficult to fit a desired flow device at a convenient location. For example, it may be necessary to fit a flow device upstream of a valve so that flow through the valve can either be measured or restricted.
A problem with such fitment is that the valve can often be positioned in a location where the conduit upstream of the valve is located in a wall or other structural component. In such a case, the only way to access such a conduit is to destroy or dismantle the structural component. As a result, even if the fitment were possible, the time spent and costs incurred in fixing or reassembling the structural component can be prohibitive.